Mass storage structure this covers a retired java programming problem. Overview of mass storage structure magnetic disks provide bulk of secondary storage of modern computers drives rotate at 60 to 250 times per second transfer rate is rate at which data flow between drive and computer positioning time randomaccess time is time to move disk arm to desired cylinder seek time and time for desired sector to rotate under the disk head rotational latency head. Secondary storage and disk scheduling algorithms secondary storage devices are those devices whose memory is non volatile, meaning, the stored data will be intact even if the system is turned off. In this chapter, we begin a discussion of file systems at the lowest level. Operating systems principle spring 2007 university of notre dame chapter 12. Hard disk platters are made of rigid metal, while floppy disks are made of more flexible plastic. Mass storage hardware this is about disk behavior and management.
A process can be swapped temporarily out of memory to a backing store, and then brought back into memory for continued execution. Chapter 10 massstorage structure operating system concepts. The choice of file system is often important in maximizing the performance of the device. In particular, design separate classes that implement the following scheduling algorithms. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Secondary storage includes memory devices that are.
Since the operating system is such a complex structure, it should be created with utmost care so it can be used and modified easily. The earliest storage devices were punched paper cards, which were used as early as 1804 to control silkweaving looms. Operating systemmass storage structure powerpoint slides. This tutorial covers magnetic disk structure and disk scheduling algorithms first come first serve, shortest seek time first and scan algorithm. In order to use mass storage, the mode must first be. The file system can be viewed logically as consisting of three parts. Mass storage is distinct from memory, which refers to temporary storage areas within the computer.
How does the os provide access to storage resources. Overview of mass storage structure disk structure disk attachment disk scheduling disk management swapspace management raid structure disk attachment stables slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Conceptually, disks are relatively simple figure 12. Chapter 12 mass storage systems linkedin slideshare. Magnetic disks provide the bulk of secondary storage for modern computer systems. To discuss operating system services provided for mass storage, including raid. The directory is itself a file, accessible by various file management routines. These storage devices are usually nonvolatile, so the contents are persistent through power failures and system reboots. Magnetic tape was early secondarystorage medium relatively permanent and holds large quantities of data access time slow random access times slower than disk mainly used for backup, storage of infrequentlyused data, transfer. An easy way to do this is to create the operating system in parts.
How does the physical design of storage devices affect the software design and performance of the os. Traditional magnetic disks have the following basic structure. Primary storage requires continuous power supply in order to maintain its state. Massstorage systems s overview of mass storage structure s disk structure s disk attachment s disk scheduling. The term storage management encompasses the technologies and processes organizations use to maximize or improve the performance of their data storage resources. The os must provide support for tertiary storage as removable media, including the support to transfer data between different systems. Apr 20, 2009 overview of mass storage structure disk structure disk attachment disk scheduling disk management swapspace management raid structure disk attachment stables slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Mass storage systems adapted from textbook slides figure 11. Lets discuss about auxillary storage also known as secondary storage in operating system. Overview of mass storage structure surendar chandra. Overview of mass storage structure magnetic disks provide bulk of secondary storage of modern computers drives rotate at 60 to 250 times per second transfer rate is rate at which data.
Abraham silberschatz, greg gagne, and peter baer galvin, operating system concepts, ninth edition, chapter 10. Much of this information, especially that is concerned with storage, is managed by the operating system. Transfer rate is rate at which data flow between drive and computer. These topics are chosen from a collection of most authoritative and best reference books on operating system. Disk characteristics space management raid disk attachment io interface how the os interfaces to the hardware the busses in the computer and how the o.
The embedded usb drive is an ideal solution for applications that require low cost and high reliability. Msds are portable storage media that provide a storage interface that can be both internal and external to the computer. Start studying operating systems 3 chapter 12 mass storage structure. A mass storage device msd is any storage device that makes it possible to store and port large amounts of data across computers, servers and within an it environment. Usb mass storage class specification overview page 9 of 9.
Now when i plug in the usb device into the computer, it is not seen on my screen, although its lights are on. Operating system notes pdf os notes pdf os pdf notes 1. In the past, operating system responsible for queue management, disk drive. Solid state disks have the same characteristics as traditional hard disks. The mass storage working group chose these brequest codes with care. Aug 17, 2018 an operating system is a construct that allows the user application programs to interact with the system hardware. They provide the bulk of secondary storage in operating systems today. In these cases, fcfs is an economical method of disk scheduling. Io systems 2 io systems this material covers silberschatz chapters 12 and. Abraham silberschatz, greg gagne, and peter baer galvin, operating system concepts, eighth edition, chapter 12 12. The operating system abstracts from the physical properties of its storage devices to define a logical storage unit, the file. Secondary storage devices are used to store data for future use or as backup. Files are mapped by the operating system onto physical devices.
I have used a usb mass storage device for years to move downloaded movies from my computer and view them on my television. In this section we present a general overview of the physical structure of secondary and tertiary storage devices. Software raid is an operating system construct, in which the os is deeply involved in mirroring the data redundantly across multiple disks. The directory contains information about the files, including attributes, location and ownership. Mass storage mode is a feature on android smartphones and blackberrys that enables devices as a removable drive when connected to a computer. It is a broad category that includes virtualization, replication, mirroring, security, compression, traffic analysis, process automation, storage provisioning and related techniques. Mass storage systems n disk structure n disk scheduling n disk management n swapspace management n raid structure n disk attachment n stablestorage implementation n tertiary storage devices n operating system issues n performance issues.
Secondary storage and disk scheduling algorithms studytonight. But look is nearly as easy to program and will give much better performance when multiple processes are performing concurrent io, such as when a web browser retrieves data in the background while the operating system is paging and another application is active in the foreground. Operating system notes pdf os pdf notes free sw 2020. Modern mass storage devices include all types of disk drives and tape drives. It might be technically possible, but it is impractical.
One should spend 1 hour daily for 23 months to learn and assimilate operating system comprehensively. The first few codes assigned for the bbb transport do not alias the first few codes assigned for core usb requests because the working group counted down from ffh to choose new codes to recommend to usbif. Chapter 12 mass storage structure operating system. This storage is typically very small, ultrafast, and volatile. Operating system concepts abraham silberchatz, peter b. To describe the physical structure of secondary storage devices and its effects on the uses of the devices to explain the performance characteristics of mass storage devices to evaluate disk scheduling algorithms. Abraham silberschatz, greg gagne, and peter baer galvin, operating system concepts, eighth edition, chapter 12. In chapter 11, we examine the user and programmer interface to the file system. Explain the performance characteristics of massstorage devices discuss operatingsystem services provided for mass storage, including raid and hsm operating system concepts 8 th edition 12. Here are a few things worth noting about secondary storage.
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